1. Field of the Invention
One aspect of the present invention relates to a liposome-based drug delivery system for prolonged release at a controlled rate of a pharmacologically active compound from the site of administration to the bloodstream. The novel delivery system concerns a liposomal formulation consisting of mixture of a small portion of liposomes with encapsulated drug and a large portion of empty liposomes. The formulation increases half-life of clearance from the injection site, and has the similar release kinetics as the formulation where all liposomes contain the drug. The formulation is also convenient for scale-up process.
The second aspect of the present invention relates to the extended stability of the drug encapsulated in liposomes over the free drug. Liposome encapsulation enables the storage of the drug at very low overall concentration at which the free drug would have lost its activity.